Add native AAudio low-latency renderer

README.md

@@ -46,6 +46,7 @@ If you switch back to the main stream version, you'll be missing the following a
 29. Server Command integration with [Apollo](https://github.com/ClassicOldSong/Apollo)
 30. Clipboard sync (requires Apollo)
 31. SBS 3D for external Displays (Using AI MiDaS v2 Lite)
+32. Native AAudio low-latency audio renderer on Android O+ when system audio effects are disabled, with AudioTrack fallback.
 
 # Disclaimer
 

app/src/main/java/com/limelight/Game.java

@@ -9,7 +9,7 @@
 import static com.limelight.utils.ServerHelper.getSecondaryDisplay;
 
 import com.limelight.binding.PlatformBinding;
-import com.limelight.binding.audio.AndroidAudioRenderer;
+import com.limelight.binding.audio.LowLatencyAudioRenderer;
 import com.limelight.binding.input.ControllerHandler;
 import com.limelight.binding.input.GameInputDevice;
 import com.limelight.binding.input.KeyboardTranslator;
@@ -873,7 +873,7 @@ public void notifyCrash(Exception e) {
                 decoderRenderer.setRenderTarget(streamContainer.getSurface());
 
                 // Starten Sie die NvConnection
-                conn.start(new AndroidAudioRenderer(Game.this, prefConfig.playHostAudio),
+                conn.start(new LowLatencyAudioRenderer(Game.this, prefConfig.enableAudioFx),
                         decoderRenderer, Game.this);
             }
         });

app/src/main/java/com/limelight/binding/audio/LowLatencyAudioRenderer.java

@@ -0,0 +1,86 @@
+package com.limelight.binding.audio;
+
+import android.content.Context;
+
+import com.limelight.LimeLog;
+import com.limelight.nvstream.av.audio.AudioRenderer;
+import com.limelight.nvstream.jni.MoonBridge;
+
+public class LowLatencyAudioRenderer implements AudioRenderer {
+    // Some Android TV devices deny AudioTrack's fast path even when low-latency
+    // mode is requested. Prefer AAudio's callback path on Android O+ to avoid
+    // those device-specific AudioTrack latency spikes, then fall back if needed.
+    private final AndroidAudioRenderer audioTrackRenderer;
+    private final boolean enableAudioFx;
+    private boolean useNativeAAudio;
+
+    public LowLatencyAudioRenderer(Context context, boolean enableAudioFx) {
+        this.audioTrackRenderer = new AndroidAudioRenderer(context, enableAudioFx);
+        this.enableAudioFx = enableAudioFx;
+    }
+
+    @Override
+    public int setup(MoonBridge.AudioConfiguration audioConfiguration, int sampleRate, int samplesPerFrame) {
+        if (!enableAudioFx && NativeAAudioRenderer.isSupported()) {
+            int result = NativeAAudioRenderer.setup(audioConfiguration, sampleRate, samplesPerFrame);
+            if (result == 0) {
+                useNativeAAudio = true;
+                return 0;
+            }
+
+            LimeLog.info("Native AAudio renderer setup failed; falling back to AudioTrack: " + result);
+            NativeAAudioRenderer.cleanup();
+        }
+        else if (enableAudioFx) {
+            LimeLog.info("Audio effects enabled; using AudioTrack renderer");
+        }
+
+        return audioTrackRenderer.setup(audioConfiguration, sampleRate, samplesPerFrame);
+    }
+
+    @Override
+    public void start() {
+        if (useNativeAAudio) {
+            NativeAAudioRenderer.start();
+        }
+        else {
+            audioTrackRenderer.start();
+        }
+    }
+
+    @Override
+    public void stop() {
+        if (useNativeAAudio) {
+            NativeAAudioRenderer.stop();
+        }
+        else {
+            audioTrackRenderer.stop();
+        }
+    }
+
+    @Override
+    public void playDecodedAudio(short[] audioData) {
+        if (MoonBridge.getPendingAudioDuration() >= 40) {
+            LimeLog.info("Too much pending audio data: " + MoonBridge.getPendingAudioDuration() + " ms");
+            return;
+        }
+
+        if (useNativeAAudio) {
+            NativeAAudioRenderer.playDecodedAudio(audioData);
+        }
+        else {
+            audioTrackRenderer.playDecodedAudio(audioData);
+        }
+    }
+
+    @Override
+    public void cleanup() {
+        if (useNativeAAudio) {
+            NativeAAudioRenderer.cleanup();
+            useNativeAAudio = false;
+        }
+        else {
+            audioTrackRenderer.cleanup();
+        }
+    }
+}

app/src/main/java/com/limelight/binding/audio/NativeAAudioRenderer.java

@@ -0,0 +1,51 @@
+package com.limelight.binding.audio;
+
+import android.os.Build;
+
+import com.limelight.LimeLog;
+import com.limelight.nvstream.jni.MoonBridge;
+
+final class NativeAAudioRenderer {
+    private NativeAAudioRenderer() {}
+
+    private static final boolean SUPPORTED = Build.VERSION.SDK_INT >= Build.VERSION_CODES.O && nativeIsSupported();
+
+    static boolean isSupported() {
+        return SUPPORTED;
+    }
+
+    static int setup(MoonBridge.AudioConfiguration audioConfiguration, int sampleRate, int samplesPerFrame) {
+        if (!SUPPORTED) {
+            return -1;
+        }
+
+        int result = nativeSetup(audioConfiguration.channelCount, sampleRate, samplesPerFrame);
+        if (result == 0) {
+            LimeLog.info("Using native AAudio renderer for low-latency audio");
+        }
+        return result;
+    }
+
+    static void start() {
+        nativeStart();
+    }
+
+    static void stop() {
+        nativeStop();
+    }
+
+    static void playDecodedAudio(short[] audioData) {
+        nativeWrite(audioData, audioData.length);
+    }
+
+    static void cleanup() {
+        nativeCleanup();
+    }
+
+    private static native boolean nativeIsSupported();
+    private static native int nativeSetup(int channelCount, int sampleRate, int samplesPerFrame);
+    private static native void nativeStart();
+    private static native void nativeStop();
+    private static native void nativeWrite(short[] audioData, int sampleCount);
+    private static native void nativeCleanup();
+}

app/src/main/jni/moonlight-core/Android.mk

@@ -40,6 +40,7 @@ LOCAL_SRC_FILES := moonlight-common-c/src/AudioStream.c \
                    moonlight-common-c/enet/win32.c \
                    simplejni.c \
                    callbacks.c \
+                   aaudio_renderer.c \
                    minisdl.c \
 
 
@@ -53,7 +54,7 @@ ifeq ($(NDK_DEBUG),1)
 LOCAL_CFLAGS += -DLC_DEBUG
 endif
 
-LOCAL_LDLIBS := -llog
+LOCAL_LDLIBS := -llog -ldl
 
 LOCAL_STATIC_LIBRARIES := libopus libssl libcrypto cpufeatures
 LOCAL_LDFLAGS += -Wl,--exclude-libs,ALL